The Stars confirmed to AAP that the pair tested positive on Tuesday but from this summer, the BBL is permitting teams and COVID-positive players to make the call on whether they feel comfortable playing while infected.
To minimise the spread of the infection, the pair travelled to the ground in a separate vehicle from their teammates, have their own dressing room and will not sit with the team in the dugout.
The last-minute COVID-19 cases won't have felt unfamiliar for Adam Zampa's men; the Stars were one of the teams hardest hit by outbreaks last summer.
Taken by the Stars with the third pick of the inaugural draft, veteran New Zealand international Trent Boult will make his BBL debut against the Thunder, while Englishman Luke Wood is also playing in the tournament for the first time.
Another notable inclusion in the Stars' XI is Tom Rogers, who signed with the side late last week as a replacement for injured captain Glenn Maxwell.
Fresh from racking up the highest individual score of the 2022 T20 World Cup (109), Rilee Rossouw makes his Thunder debut having last played in the tournament for the Melbourne Renegades two summers ago.
Paceman Fazalhaq Farooqi, signed after David Willey withdrew from the tournament, will make his BBL debut for the Thunder as the side's first-ever Afghan player.
Melbourne Stars: Tom Rogers, Joe Clarke, Joe Burns, Nick Larkin, Marcus Stoinis, Hilton Cartwright, Beau Webster, Luke Wood, Nathan Coulter-Nile, Adam Zampa (capt), Trent Boult.
Sydney Thunder: Alex Hales, Matthew Gilkes, Rilee Rossouw, Jason Sangha (capt), Daniel Sams, Alex Ross, Ollie Davies, Chris Green, Gurinder Sandhu, Fazalhaq Farooqi, Brendan Doggett.
